applets/taskmanager: Use `PlasmaCore.Units.largeSpacing` to estimate width/height

The spacing between tasks is `PlasmaCore.Units.largeSpacing`, not
`2*PlasmaCore.Units.smallSpacing`.

applets/taskmanager/package/contents/ui/ToolTipDelegate.qml

@@ -99,8 +99,8 @@ Loader {
                     id: delegateModel
 
                     // On Wayland, a tooltip has a significant resizing process, so estimate the size first.
-                    readonly property int estimatedWidth: (toolTipDelegate.isVerticalPanel ? 1 : count) * (toolTipDelegate.tooltipInstanceMaximumWidth + PlasmaCore.Units.smallSpacing * 2) - PlasmaCore.Units.smallSpacing * 2
-                    readonly property int estimatedHeight: (toolTipDelegate.isVerticalPanel ? count : 1) * (toolTipDelegate.tooltipInstanceMaximumWidth / 2 + PlasmaCore.Units.smallSpacing * 2) - PlasmaCore.Units.smallSpacing * 2
+                    readonly property int estimatedWidth: (toolTipDelegate.isVerticalPanel ? 1 : count) * (toolTipDelegate.tooltipInstanceMaximumWidth + PlasmaCore.Units.largeSpacing) - PlasmaCore.Units.largeSpacing
+                    readonly property int estimatedHeight: (toolTipDelegate.isVerticalPanel ? count : 1) * (toolTipDelegate.tooltipInstanceMaximumWidth / 2 + PlasmaCore.Units.largeSpacing) - PlasmaCore.Units.largeSpacing
 
                     model: tasksModel